Waveguide edge light shielding composition having excellent adhesive strength
An ultraviolet curable composition and a waveguide manufactured from the same are disclosed herein. In an embodiment, an ultraviolet curable composition for light shielding of a waveguide, comprises a colorant, an acrylate monomer, a urethane acrylate oligomer, an organosilane and a photopolymerization initiator, wherein adhesion between the cured composition and a glass substrate is 5B or greater by a ASTM D3359 standard and/or is 1,500 mN or greater by a microscratch test (MST).
1. An ultraviolet (UV) curable composition for light-shielding a rim side of a waveguide, comprising:
a colorant, acrylate monomers, a urethane acrylate oligomer, an organosilane, and a photopolymerization initiator,
wherein the acrylate monomers comprise a monofunctional acrylate monomer, a bifunctional acrylate monomer, and a polyfunctional acrylate monomer,
wherein the content of the monofunctional acrylate monomer is 5 to 40% by weight and the content of the bifunctional acrylate monomer and the multifunctional monomer is from 10 to 70% by weight, based on the total weight of the composition,
wherein a weight ratio of the acrylate monomers to the urethane acrylate oligomer is 2:1 to 6:1, and
wherein, after curing the UV curable composition, adhesion between the cured composition and a glass substrate is 5B or more in accordance with ASTM D3359 standard, and 1500 mN or more in accordance with a microscratch test (MST).
2. The UV curable composition according to claim 1 , wherein the composition further comprises at least one selected from the group consisting of a photosensitizer and a surfactant.
3. The UV curable composition according to claim 1 , wherein the acrylate monomers comprises at least one selected from the group consisting of tetrahydrofurfuryl acrylate, cyclic trimethylolpropane formal acrylate, bisphenol A epoxy diacrylate, hydroxypivalic neopentyl glycol diacrylate, trimethylolpropane triacrylate, tris(2-hydroxyethyl)isocyanurate triacrylate, pentaerythritol tetraacrylate, 2-hydroxyethyl acrylate and dipentaerythritol hexaacrylate.
4. The UV curable composition according to claim 1 , wherein the content of the colorant is 0.1 to 15% by weight based on the total weight of the composition.
5. The UV curable composition according to claim 1 , wherein the content of the urethane acrylate oligomer is 0.5 to 30% by weight based on the total weight of the composition.
6. The UV curable composition according to claim 1 , wherein the composition is capable of being cured by UV light in a wavelength range of 250 nm to 450 nm.
7. The UV curable composition according to claim 1 , wherein the composition is capable of being cured by UV light in a wavelength range of 360 nm to 410 nm.
8. A planar waveguide, comprising:
a waveguide having a first surface and an opposing second surface separated by a thickness therebetween, where the first and second surfaces extend to a rim side, wherein the rim side extends along the thickness of the waveguide, the rim side having a cut surface; and
a light-shielding film disposed on the cut surface of the rim side of the waveguide,
wherein the light-shielding film is prepared by curing the UV curable composition of claim 1 ,
wherein the total optical density of the light-shielding film is 1.5 or more, and
wherein adhesion between the waveguide and the light-shielding film is 5B or more in accordance with ASTM D3359 standard, and 1500 mN or more in accordance with a microscratch test (MST).
9. The planar waveguide according to claim 8 , wherein the colorant of the light-shielding film is at least one black ink pigment selected from the group consisting of carbon black, graphite, metal oxide and organic black pigments.
10. The planar waveguide according to claim 8 , wherein the content of the black ink pigments is 0.1 to 15% by weight based on the total weight of the light-shielding film.
11. A waveguide module comprising the waveguide according to claim 8 .
12. A method of manufacturing a planar waveguide, comprising:
coating the composition according to claim 1 on a cut surface of a rim side of a waveguide, wherein the waveguide has a first surface and an opposing second surface separated by a thickness therebetween, wherein the first and second surfaces extend to the rim side, wherein the rim side extends along the thickness of the waveguide, the rim side having the cut surface; and
curing the composition to form the light-shielding film having an optical density (OD) of 1.5 or more.
13. The method according to claim 12 , wherein coating the composition further comprises:
coating the curable ink composition on the cut surface of the rim side of the waveguide using a dispenser process or an inkjet printing method.
14. The method according to claim 12 , wherein the curing is UV curing.
15. The method according to claim 12 , wherein adhesion between the waveguide and the light-shielding film is 5B or more in accordance with ASTM D3359 standard, and 1500 mN or more in accordance with a microscratch test (MST).
16. The method according to claim 12 , wherein the cut surface is a planar surface, a curved surface, or an inclined surface.
17. The method according to claim 12 , wherein the light-shielding film is disposed on the first and second surfaces at a periphery thereof.